My first full marathon was Khon Kaen , Jan. 2011 , I was 58 years old at the time and my body said the same thing,. but my head over-ruled it and I signed up for 4 more that year namely Rome , Paris , Edinburgh and Singapore and also the Great North Run , as they say "there's no fool like an old fool".
Still running marathons at 72 , planning on doing Sydney , Cape Town and Beijing next...🏃♂️